Design And Realization Of County Land Intensive Utilization Evaluation And Analysis System Based On The KML Format

As the application of the Geographic information system, land information system changed the traditional management method which is based on tables, and has realized the unified management of land uses graphic data and attributes data. But the expressing form of graphics in GIS software is still not very intuitionistic, the presentation content is still not very rich. Google Earth is a nicer open 3D data shown platform, which syncretizes a great deal of remote sensing image and geographic coordinate information. In view of this, this paper studies the function and application of Google Earth, and studies the development status of land system, and then the application of Google Earth in land is proposed. The purpose of this paper is to build a three dimensional county land intensive utilization evaluation and analysis system with perfect functions, which is based on KML data form and Google Earth platform.Based on studies of the function of GE COM API and the grammar form of KML, the paper explores the thought of secondary development of GE, and summarizes the function could be realized by secondary development of GE and the shortcomings. Then design the software according to the basic flow of software design of software engineering: analyze requirement, propose three-tier architecture, build system platform, design system function, design system database, program and realize system by c# language with key technology and main algorithm. At last, a case was given to verify the feasibility and scientificalness of system.When design the system database, according to storage form, all the data was divided into two types: KML document and attribute database. Based on the study on grammar form of KML and the using of GE COM API function, system interface was integrated with Google Earth interface; GIS data was transformed to KML document by ArcEngine interface; the function of drawing point,polyline,polygon and island polygon on GE interface was realized, the function of image overlay was realized, the function of survey distance and area was realized, the function of extract altitude information was realized, the function of transforming image to KML document was realized, the function of transforming between database and KML document was realized. Based on the study on database technology, the function of attribute data management and the query of data was realized, the function of computation and classification of intensive degree was realized, and the function of report analysis was realized.In the chapter of application, took Miyun County in Beijing as an example, application of system was introduced simply, and by the system, the intensive degree of the villages in Henanzhai town Miyun county were evaluated, the impact factors of intensive degree were analyze. The scientificalness of system was proved.